X Chromosomal Studies of Spermatogenic Failure

项目摘要 这一提议假定，对参与物种形成的快速进化基因的研究将提供重要的 深入了解男性不育的人类分子遗传学。物种形成是两个 种群在繁殖上变得孤立。在最近分化的物种之间，生殖隔离 通常表现为男性不育X染色体上快速进化的基因 这种生殖隔离的主要驱动因素。我的初步研究发现， 以大的、近乎完美的片段复制或扩增子形式存在的基因。我假设 这些X-扩增子序列含有精子发生的关键基因， 一个物种内的基因序列会导致雄性不育。我将在人类和老鼠身上进行研究来验证这一点 假说.在人类中，X染色体的所有扩增子都将被准确测序，以确定它们的基因序列。 基因组结构在每个扩增区域的分辨率，我将确定在何种程度上，X- 扩增产物缺失与生精障碍显著相关; 不孕为了做到这一点，我将在500名生精失败的男性和500名 控制人群中的男性。检测人类X-扩增子基因在精子发生中是否表达， 细胞，我将进行X-扩增子基因的表达谱分析，以提供深入了解分子 生精障碍的发病机制。在小鼠中，12%的X染色体由扩增子组成。 序列的两个X-扩增子区域是特别感兴趣的，因为它们代表了最快速的 X染色体的进化区域，并与杂交小鼠的精子发生失败有关。因此，在本发明中， 这两个X-扩增子区域代表了研究精子发生功能的非常有希望的候选者。 X-扩增子基因。为了测试这两个X-扩增子区域是否在精子发生障碍中起作用，我 将产生两个区域的独立靶向敲除。小鼠X-扩增子区域的基因敲除 提供了机会来执行在人类中不可行的受控功能丧失和拯救实验。的 人类的DNA研究加上小鼠X-扩增子基因的分子特征将是 这对于我们进一步了解X-扩增子基因在人类精子发生中的功能至关重要， 生殖

PROJECT SUMMARY This proposal posits that the study of rapidly evolving genes involved in speciation will provide significant insights into the human molecular genetics of male infertility. Speciation is the process by which two populations become reproductively isolated. Between recently diverged species, reproductive isolation typically manifests itself in the form of male infertility. Rapidly evolving genes on the X chromosome are primary drivers of this reproductive isolation. My preliminary studies have identified rapidly evolving X-linked genes which are harbored in large, near-perfect, segmental duplications, or amplicons. I hypothesize that these X-ampliconic sequences contain genes critical for spermatogenesis and that the rapid evolution of these sequences within a species can lead to male infertility. I will perform studies in humans and mice to test this hypothesis. In humans, all amplicons of the X chromosome will be accurately sequenced to determine their genomic architecture. Upon resolution of each ampliconic region, I will determine the extent to which X- ampliconic deletions are significantly associated with spermatogenic failure; the most common type of male infertility. To do this I will screen for deletions in a collection of 500 men with spermatogenic failure and 500 men from a control population. To test whether human X-ampliconic genes are expressed in spermatogenic cells, I will perform expression profiling of X-ampliconic genes to provide insight into the molecular pathogenesis of spermatogenic failure. In mice, 12% of the X chromosome is comprised of ampliconic sequences. Two X-ampliconic regions are of particular interest because they represent the most rapidly evolving regions of the X chromosome and have been linked to spermatogenic failure in hybrid mice. Thus, these two X-ampliconic regions represent highly promising candidates to study the spermatogenic functions of X-ampliconic genes. To test whether these two X-ampliconic regions have a role in spermatogenic failure, I will generate independent targeted knockouts of both regions. The knockout of X-ampliconic regions in mice offers opportunities to perform controlled loss-of-function and rescue experiments not feasible in humans. The DNA studies in humans coupled with molecular characterizations of X-ampliconic genes in mice will be essential to advance our understanding of X-ampliconic gene functions in human spermatogenesis and reproduction.